Give me someone bold enough to describe a world I’ve never been to.
I'm sure you can find a few exceptions to the rule, but mostly, once a reader is settled in to the setting, he or she wants something to happen. Plot should unroll. There should be something for the reader to worry about: will the crew escape the dreadful lizard folk? A question to be resolved: what did happen to the missing settlers of Orion IV? Will ____ be destroyed? Even, will John finally get up the courage to face down Bob and marry Mary, the half Orion slave girl?
Jayson Merryfield
Basically, they are about what happens on a planet after a spaceship has landed there accidentally (so it is a totally unknown planet), and how they learn about this new world and figure out how to survive on it.
My favorite one is probably POLYMATH by John Brunner. Marion Zimmer Bradley wrote one called DARKOVER LANDFALL, and Anne McCaffrey wrote one that I hated called DRAGONDAWN.
There is a variation on that kind of story that involves a planet people know about, but they don't know if there is sentient life on it, so the story is about how they learn how life works on the planet, and that there really is sentient life and how to communicate with it.
OSC's SPEAKER FOR THE DEAD is partly this kind of story. Sheri Tepper wrote a couple of them, that I know of (and that I liked): GRASS and AFTER LONG SILENCE.
If you really want to be shown a world you've never been to, I'd recommend that you try to find a copy of Brunner's POLYMATH and read it.
As for travelogues, you could look for Leigh Brackett's ERIC JON STARK stories. They explore some pretty cool worlds.
Yet, unfortunately, I'm still interested in writing science fiction. Certainly nothing else grabs at me wanting me to write it, though a few notions come up from time to time. (I'm somewhat less enamored of publishing what I write of late, but that's another story.)
As for Asimov...well, Nemesis really isn't the place to start. It was, I think, his second-to-last novel...he was not terribly enamored of writing all these late novels, I gather, but did it to please his publisher...and he was also in the throes of ill health, which, I think, may have shown in the work.
If you're looking for prime Asimov, try the Foundation trilogy (Foundation, Foundation and Empire, Second Foundation), or the stories that make up I, Robot, or The Caves of Steel, or shorter stories like "Nightfall" or "The Martian Way," written where Asimov was younger and healthy and firing on all cylinders.
(Aside note about pulp fiction: somebody just reprinted some of the Doc Savage novels, printed in pulp magazine size (but much more neatly). I saw some yesterday at the Barnes & Noble, in a special stand, commemorating the seventy-fifty anniversary of their first publication. Pick up some of 'em, if you never have before.)
If you want to give the genre another try and are drawn toward the Golden Age authors who have that wonder and awe in their works, I suggest The Moon is a Harsh Mistress by Heinlein, Foundation by Asimov (or any in the Robot series, which are mystery in style/structure rather than travelogue), or the Rama series by Arthur C. Clarke (which I keep talking about. He doesn't do deep POV immersion, and tends toward omnicient POV, which I find pretty odd to read in this day and age, yet I really enjoyed the books.)
I wouldn't start with any of the 2001 books, either. The original is at variance with the movies...the later ones spend a lot of time exploring the future and less time with the monolith...
I'd start with some of Clarke's earlier stuff...say, Childhood's End or Earthlight...there's also The City and the Stars, which probably takes things further than any other of Clarke's novels...Prelude to Space and The Sands of Mars are good, but have really badly aged by subsequent events in real life.
You might sample some of the stories in a massive "Complete Short Stories" collection published a few years ago...you should still be able to find a copy...
Once you get hooked, you'll move on to most of these other works. I don't know what's in print right now. (Beware! Childhood's End exists in at least two different editions, both with different beginnings. Either are okay but the meat is further on in the story.)